A Swedish pulp mill has removed the costly practice of manually measuring vibrations and performance of numerous motors installed on a pulp dryer, by installing ABB Ability™ Smart Sensors from ABB.
Södra Cell’s pulp dryer features 140 motors controlling fans that are used to dry the wet timber before it enters the dryer. There are two banks each containing 70 fans and their associated motors. Initially, half the installed base of motors were fitted with Smart Sensors. Following the successful trial, the remaining 70 motors are also being fitted with Smart Sensors.
The banks of fans are stacked in such a way that an aerial platform lift was needed to give engineers access so they could manually take vibration measurements. This monthly requirement incurred costs for the platform, the qualified engineer and the vibration analysis equipment.
Following installation of the ABB AbilityTM Smart Sensor, Södra Cell can now closely track the performance of individual motors, remotely, thereby avoiding cost of the manual approach. Under a service agreement, the motors are remotely monitored constantly, with the Smart Sensors taking measurements every hour. Previously, vibration measurements were taken manually, once a month. Now Södra Cell’s engineers are available to focus on other tasks.
ABB provides the company with a clear indication of how each motor is performing at different operational speeds, enabling them to optimize their pulp drying process. ABB engineers also raise any alerts if, for instance, they identify any unusual vibration patterns that might lead to premature failure.
The Smart Sensors are attached, without any wiring, to the outer casing of the motors. The sensors are used to track the motor’s speed, vibration levels, sheath temperature, frequency of starts/ stops, operating time and power consumed, which is then analyzed via a secure cloud service.
Södra Cell operates one of the world’s most modern pulp mills, producing 750,000 tonnes of pulp per year. The company prides itself on having a nearly fully automated plant, self-sufficiency in electricity and meeting 98 percent of its heating needs with biofuels. In 2019, the mill was the first operation in Sweden to be awared ”World-class maintenance” status by the auditor Trivalo which highlighted the company’s ‘competent and long-term efforts’ and maintenance operations which have been established ‘at a level of world-class excellence’.
”There are always areas for improvement, but we are often excessively self-critical in our eagerness to become better and therefore sometimes miss how good we are,” says Thomas Håkansson, Head of Maintenance at Södra Cell in Mönsterås. “We have worked purposefully since 2003 to achieve properly-functioning and efficient maintenance that creates added value through a high level of availability and consistent quality.”
“Using the Smart Sensors for vibration monitoring on the pulp dryer motors gave us a good opportunity to assess the intelligence of these devices,” says Andreas Eriksson, Maintenance Technician at Södra Cell. “Previously, condition monitoring was performed by measuring total vibrations with hand instruments. This was very time consuming. Now, with the Smart Sensor, measurements are taken every hour which gives us much better insights into the health and performance of our motors.”
“Maintenance can now be planned according to current needs rather than based on general schedules. It extends the life of the equipment, reduces maintenance costs and reduces or eliminates unplanned downtime. In addition, we obtain new data that can be used for systematic investigations to identify problem sources and improve the process or reliability of the system.”
And finally, using the smart sensors helps to enhance the safety of the site as Erik Bohman, Service Manager Motors and Generators at ABB in Sweden explains: “One of the advantages of Smart Sensors is that the motors can be measured without risk when, for example, they are near rotating parts or where lifts and scaffolding are needed to access manually.”